Moving a first vehicle into precise position relative to another vehicle is often difficult inasmuch as the operator of the moving vehicle is not in a position to view the close relationship of those parts of the two vehicles which determine the desired relative positions of the vehicle. In instances wherein one vehicle must be moved to a precise position relative to another vehicle, an observer is often utilized to assist the driver of the movable vehicle with hand and voice signals. However, an observer is not always available and even when a person is available to act as an observer he or she may not be skilled in the art of directing the operator of the movable vehicle into the precise desired position. Accordingly, a need exists for a guidance device whereby the operator of a first vehicle may move the first vehicle into precise position relative to a second vehicle.
Various forms of guidance devices specifically designed for this purpose have been heretofore designed and are disclosed in U.S. Pat. Nos. 3,605,088, 3,731,274, 3,825,921, 3,938,122 and Re. 28,590.